Impedance is a term used in electrical engineering to describe the opposition to the flow of an alternating current. The crossword solutions for this term are CLOG (4 letters), RESISTANCE (10 letters), HINDRANCE (9 letters), and BLOCKAGE (8 letters). CLOG refers to an obstruction that prevents or hinders the flow of a liquid or gas. RESISTANCE is the opposition to the flow of electric current, which is a measure of impedance. HINDRANCE is an obstacle that makes progress difficult or slow. BLOCKAGE is an obstruction that prevents or restricts the passage of something.